Can't speak for L.A. proper, but Aloha (several locations in the Valley) carries several USIA suits you could check out. They also carry Bare and Whites, if memory serves, but I don't know how many (if any) they have in stock. They may carry Diving Concepts as well. USIA is their big push, however, and they definitely have those in stock.
As far as rentals, I've heard of places in other states that rent out cheap Bare Next-Gens, but locally the only rentals I've seen are DUI. Not sure if Aloha rents their USIAs or not.